The project continues current work on cardiovascular, pulmonary, neuromuscular, tissue perfusion, and CNS studies designed to provide continuous physiologic data and, where possible, predictive diagnosis in high-risk surgical patients. The overall goal is to develop concepts, design instruments, and evaluate strategies using old and new concepts and instruments in the care of surgical patients in an effort to reduce peri-operative morbidity and mortality related to failure in the vital functions of brain, heart, and lung. The project is highly integrated. Teams carrying out the physiologic organ system research interact with teams engaged in technological R and D designed to support the entire program. Thus, the problems addressed range from studies of neuromuscular integrity and its relationship to ventilation, to the acquisition and transmission of non-physiologic data from operating rooms to control stations; from the study of autonomic control of the heart to multilevel adaptive modeling of a clinical situation. This project is strongly oriented to the surgical patient and all research efforts finally flow together for application and clinical evaluation in a laboratory of biomedical engineering composed of at least four busy clinical operating rooms with redundant connections to an anesthesia monitoring and computer room.